riscv: __asm_copy_to-from_user: Fix: overrun copy

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There were two causes for the overrun memory access.

The threshold size was too small.
The aligning dst require one SZREG and unrolling word copy requires
8*SZREG, total have to be at least 9*SZREG.

Inside the unrolling copy, the subtracting -(8*SZREG-1) would make
iteration happening one extra loop. Proper value is -(8*SZREG).

Signed-off-by: Akira Tsukamoto <akira.tsukamoto@gmail.com>
Fixes: ca6eaaa210 ("riscv: __asm_copy_to-from_user: Optimize unaligned memory access and pipeline stall")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

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Akira Tsukamoto 2021-07-20 17:50:52 +09:00 • committed by Palmer Dabbelt

parent 76f5dfacfb

commit 6010d300f9

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arch/riscv/lib/uaccess.S

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